Its D. The gene transfer to non
Explanation:
it is made up of more than one simple machine...think compound sentences are multiple simple sentences together so compound machines are multiple simple machines together
Answer:
used in an experiment as a way to ensure that your experiment actually work
Explanation:
The first one is atoms cause they are all the same type of particles. The blue one is the molecules that is not compound cause they aren't connected to each other. The other two are compound cause two atoms of two different elements are bonded together.